One of my badminton acquaintances asked if I'd heard of Numba (wiki, github).  It seems to have a role similar to that of Cython, while requiring even less intrusive changes to the code.

Chances are that someone else on the list will have a better idea of whether we might be interested in using it in the future.  There's a couple of blog posts here and here comparing Numba with Cython; they seem to have similar execution speeds so it's unlikely to be worth rewriting existing code.